DTC P1500: Engine Start Signal Circuit Malfunction

Measure voltage (backprobe) between ground and Black/Yellow wire at PCM 16-pin harness connector C22 terminal No. 16 (Esteem 1.6L and Swift) or between ground and PCM connector C20-15 (Esteem 1.8L) while cranking engine. Reading should be 6-10 volts. After engine starts, voltage should drop to zero. If readings are not as specified, repair open in Black/Yellow wire between starter and PCM. If readings are as specified, check for poor connection at PCM. If connections are okay, replace PCM.